Earth Talk

How Safe is our Drinking Water?

Dear EarthTalk:Bottled water companies would have us all believe that
tap water is unsafe to drink. But I've heard that most tap water is actually pretty
safe. Is this true?

-- Sam Tsiryulnikov, Los Angeles, CA

Tap water is not without its problems. The nonprofit Environmental Working Group (EWG)
in 2005 tested municipal water in 42 states and detected some 260 contaminants in public
water supplies, 140 of which were unregulated chemicals, that is, chemicals for which
public health officials have no safety standards for, much less methods for removing them.

EWG did find over 90 percent compliance on the part of water utilities in applying and
enforcing standards that exist, but faults the U.S. Environmental Protection Agency (EPA)
for failing to establish standards on so many of the contaminants—from industry,
agriculture and urban runoff—that do end up in our water.

Despite these seemingly alarming stats, the Natural Resources Defense Council (NRDC),
which has also conducted extensive municipal as well as bottled water tests, says:
"In the short term, if you are an adult with no special health conditions, and
you are not pregnant, then you can drink most cities' tap water without having to
worry." This is because most of the contaminants in public water supplies exist
at such small concentrations that very large quantities would need to be ingested for
health problems to occur.

NRDC does caution, however, "that pregnant women, young children, the elderly, people
with chronic illnesses and those with weakened immune systems can be especially vulnerable
to the risks posed by contaminated water." The group suggests that anyone at risk obtain
a copy of their city's annual water quality report (they are mandated by law) and review it
with their physician.

As for bottled water, it is first important to know that 25 to 30 percent of it comes
straight from municipal tap water systems, despite the pretty nature scenes on the bottles
that imply otherwise. Some of that water goes through additional filtering, but some does
not. NRDC has researched bottled water extensively and has found that it is "subject
to less rigorous testing and purity standards than those which apply to city tap water."
Bottled water is required to be tested less frequently than tap water for bacteria and chemical
contaminants, and U.S. Food and Drug Administration bottled water rules allow for some
contamination by E. coli or fecal coliform, contrary to EPA tap water rules which prohibit
any such contamination.

Similarly, NRDC found that there are no requirements for bottled water to be disinfected or
tested for parasites such as cryptosporidium or giardia, unlike more stringent EPA rules
regulating tap water. This leaves open the possibility, says NRDC, that some bottled water
may present similar health threats to those with weakened immune systems, the elderly and
others they caution about drinking tap water.

The bottom line is that we have invested considerably in highly efficient municipal water
delivery systems that bring this precious liquid straight to our kitchen faucets anytime we
need it. Instead of taking that for granted and relying on bottled water instead, we need to
make sure our tap water is clean and safe for all.